Russian resolution ... a poster for the Royal Academy exhibition. Photograph: Sang Tan/AP

A blockbuster exhibition of paintings from Moscow and St Petersburg will go ahead as planned after Russian authorities confirmed the loans had been approved. The Royal Academy show, From Russia: French and Russian Master Paintings 1870-1925, will now go ahead in London on January 26 2008.

Doubt was cast after Russia withdrew permission for the loan of the masterpieces for the exhibition fearing legal action from descendants claiming ownership of the paintings. Permission was eventually granted after "maximum possible assurances" were given from the British government and new legislation was fast-tracked to protect art from seizure.

The Royal Academy received official notification yesterday from Mikhail Shvydkoi, director of the Russian federal agency for culture and cinematography, approving the loans. Shvydkoi said: "Having consulted with colleagues from the ministry of foreign affairs, we have come to the conclusion that, having received the maximum possible assurance of the British government, there is therefore every reason to permit the holding of such exhibition in the designated time frame - from January 26 to April 18 2008."

Charles Saumarez Smith, the chief executive of the Royal Academy, said that the body was "absolutely delighted". He praised the "enormous help and close collaboration" from the department for culture, media and sport, the federal agency for culture and cinematography, the Russian embassy in London and the British embassy in Moscow as well as the four Russian state museums. "We are grateful to them all," he said.

A diplomatic spat between Russia and the UK ensued in the aftermath of the murder of former KGB agent Alexander Litvinenko in London, but both governments denied this was a factor. The frosty relations saw the British Council, a non-political body that acts as a cultural department for the British embassy, ordered to shut down virtually its entire operation. Russia previously said that it would issue licences for the paintings, which include works by Renoir, Cezanne, Van Gogh and Picasso, to go to the Royal Academy once the legislation was implemented. But officials stressed that "the law must ensure the art's immunity from seizure".

The new legislation is Part 6 of the Tribunals, Courts and Enforcement Act 2007, which received royal assent in July 2007. Part 6 of the act means descendants of the original owners cannot bring their claims on British soil. The legislation is intended to ensure that cultural objects can be loaned for exhibition in the UK without fear that they may be subject to seizure or forfeiture and brings Britain in line with the rest of Europe.

The exhibition attracted more than 200,000 visitors in Düsseldorf, Germany, where it had been on show before it transfers to London.